The present invention relates to a cleaning system for a telephone number list in a customer list and so forth to be used in telemarketing and the like, for deleting null telephone numbers from the telephone number list using such an apparatus as a personal computer.
In various businesses utilizing a telephone, a telephone number list of customers is quite important information and thus has to be maintained frequently for deleting telephone numbers which have become unnecessary from the list to prevent degradation of the value of the contained information. The customer information in such lists naturally contains variable information. Namely, the telephone number of the customer may be varied due to termination of use of the registered telephone number, changing to other telephone number, and can be null because of original registration of a wrong number. Such null telephone numbers have to be deleted from the list or to be replaced with correct or new telephone numbers.
Conventionally, maintenance of a customer list has been performed upon giving a phone call to respective customers according to the telephone number list through certain business transactions. Namely, deletion or updating of the null telephone numbers has been done with verifying response from respective customers.
The conventional cleaning method for deleting and updating a telephone number list associating with business inherently may cause significant waste or irrationality in certain type of businesses. Namely, since it is not avoidable to make a phone call to the customers having null telephone numbers which should be deleted from the list, extra expense may be wasted or people who are not customers can be disturbed. On the other hand, for the customers who have moved to other addresses, it is possible to redundantly phone the old and the new numbers to cause waste both in time and cost.
In view of the above described problems in the conventional cleaning method, the present applicant has proposed a method and system for automatic and effective cleaning of a telephone number list as disclosed in U.S. Pat. No. 5,796,816 issued on Aug. 18, 1998. The proposed system utilizes advanced bearer services provided by an ISDN integrally connected with the existing public telephone network to process cleaning of a telephone number list accurately and quickly. More specifically, the cleaning system is connected with an ISDN to process circuit-switched call control procedures defined in the ITU-T recommendation Q.931 as a calling terminal. A SETUP message is sent to a telephone number retrieved sequentially from a telephone number list to be cleaned as a called party number. The SETUP message includes an unrestricted or a restricted digital information in a xe2x80x9cbearer capabilityxe2x80x9d information element to the network in the process.
The present applicant has conducted a series of functional tests of the above system to find that the system satisfactorily functions if the called parties are within an identical network, i.e., subscribe to the same service provider as the system. However, the present applicant also experienced that the system often failed to correctly receive the reply message from a destination where the SETUP message is carried over different service providers to the called parties. This seems due to different ISDN services offered by the respective service providers, which may interrupt the digital information at the interfaces therebetween.
It is an object of the present invention to provide an automatic and efficient cleaning method for a telephone number list and a system therefor, which can properly perform a process of deleting null telephone numbers using a personal computer or the like, without making phone calls on actual business basis to the subscribers to different service providers.
A cleaning method for a telephone number list and a system therefor according to the present invention, including an apparatus such as a personal computer, comprises each of the following elements (1)-(5).
(1) The system is connected with an ISDN to process circuit-switched call control procedures defined in the ITU-T recommendation Q.931 as a calling terminal.
(2) A telephone number is retrieved sequentially from a telephone number list to be cleaned as a called party number to send a SETUP message including an information selected from the group consisting of SPEECH and AUDIO in a xe2x80x9cbearer capabilityxe2x80x9d information element to the network.
(3) When the network receives the SETUP message sent and transfers an xe2x80x9calertingxe2x80x9d or xe2x80x9cconnectxe2x80x9d message, the system immediately sends a xe2x80x9cdisconnectxe2x80x9d message to the network to perform a disconnect and release sequence and determine the called party number in the SETUP message effective.
(4) When the network does not receive the SETUP message sent and transfers a xe2x80x9cdisconnectxe2x80x9d message, the system immediately performs a disconnect and release sequence and obtains a cause display in an information element of the xe2x80x9cdisconnectxe2x80x9d message from the network to determine the called party number in the SETUP message either effective or null according to the cause display.
(5) A new telephone number list is generated, which includes the telephone numbers determined effective and the telephone numbers determined null, separately.
The cleaning system according to the present invention may comprise an additional element of obtaining a new telephone number filled in a diagnosis information field appended to the cause in case that the cause transferred from the network includes xe2x80x9cNumber changedxe2x80x9d, and replacing the numbers in the SETUP message to generate a revised list with the obtained new telephone numbers. Furthermore, it may be more appropriate to defer to determine whether each of the numbers is effective or null and to put the deferred numbers in a deferred number list depending on the contents of the cause. It is possible to perform more proper cleaning of the telephone number list by checking the deferred numbers after a while.